Abstract P2-10-05: Continuous association of a 200-gene prognostic risk score with probability of neoadjuvant chemotherapy response and translation from fresh frozen to FFPE tissue for clinical use

BreastPRS is a suite of complimentary gene signatures that resolves several of the significant limitations of current gene expression signatures in breast cancer. Notably, BreastPRS can accurately provide prognosis prediction, histological grade resolution and molecular subtyping of invasive breast cancer. The 200-gene prognostic component was previously validated in an independent retrospective series of 1,016 previously published fresh-frozen breast cancers and has now been applied to data from over 6,000 patients.

In part one of this study, a meta-analysis of 890 previously published neoadjuvant treated breast cancer patients was performed. A highly significant association was observed between prognosis risk group (high vs low), continuous risk score (0–100), and a patient's probability of achieving complete pathologic response with neoadjuvant chemotherapy. Data from both fine-needle-aspirate and biopsy tissue were included in the cohort. Notably, fewer than 10% of patients with the lowest (most favorable) pre-treatment BreastPRS prognosis scores achieve pCR. Probability of pCR was observed to increase steadily to over 40% for individuals with the highest prognosis scores.

In part two of the analysis, 50 paired fresh-frozen and FFPE tumors were profiled on whole genome microarrays containing all three signatures, in a CLIA-certified high throughput genomics laboratory. Results will be presented that highlight the consistency of the prognosis, grade and subtype signatures in clinically relevant FFPE tissue.

This suggests that BreastPRS, in addition to identifying 10-year recurrence risk, histologic grade and molecular subtype, may enable physicians to determine a patients benefit from receiving neoadjuvant chemotherapy with more granularity than current clinical or genomic methods.

Impact of recent antibiotics on nasopharyngeal carriage and lower airway infection in Indigenous Australian children with non-cystic fibrosis bronchiectasis

Indigenous Australian children have increased rates of bronchiectasis. Despite a lack of high-level evidence on effectiveness and antibiotic resistance, these children often receive long-term antibiotics. In this study, we determined the impact of recent macrolide (primarily azithromycin) and β-lactam antibiotic use on nasopharyngeal colonisation, lower airway infection (>10(4) CFU/mL of bronchoalveolar lavage fluid culture) and antibiotic resistance in non-typeable Haemophilus influenzae (NTHi), Streptococcus pneumoniae and Moraxella catarrhalis isolates from 104 Indigenous children with radiographically confirmed bronchiectasis. Recent antibiotic use was associated with significantly reduced nasopharyngeal carriage, especially of S. pneumoniae in 39 children who received macrolides [odds ratio (OR)=0.22, 95% confidence interval (CI) 0.08-0.63] and 26 children who received β-lactams (OR=0.07, 95% CI 0.01-0.32), but had no significant effect on lower airway infection involving any of the three pathogens. Children given macrolides were significantly more likely to carry (OR=4.58, 95% CI 1.14-21.7) and be infected by (OR=8.13, 95% CI 1.47-81.3) azithromycin-resistant S. pneumoniae. Children who received β-lactam antibiotics may be more likely to have lower airway infection with β-lactamase-positive ampicillin-resistant NTHi (OR=4.40, 95% CI 0.85-23.9). The risk of lower airway infection by antibiotic-resistant pathogens in children receiving antibiotics is of concern. Clinical trials to determine the overall benefit of long-term antibiotic therapy are underway.

A systematic review on use of Chinese medicine and acupuncture for treatment of obesity

Obesity is a major health hazard and despite lifestyle modification, many patients frequently regain any lost body weight. The use of western anti-obesity drugs has been limited by side effects including mood changes, suicidal thoughts, and gastrointestinal or cardiovascular complications. The effectiveness and safety of traditional Chinese medicine including Chinese herbal medicine (CHM) and acupuncture provide an alternative established therapy for this medical challenge. In this systematic review, we used standard methodologies to search, review, analyse and synthesize published data on the efficacy, safety and relapse of weight regain associated with use of CHM and acupuncture. We also examined the rationale, mechanisms and potential utility of these therapies. A total of 12 electronic databases, including Chinese, English, Korean and Japanese, were searched up to 28 February 2010. Randomized controlled trials (RCTs) for CHM and/or acupuncture with comparative controls were considered. We used the Jadad scale to assess methodological qualities, the random effect model in the pooled analysis of therapeutic efficacy to adjust for heterogeneity and funnel plots to explore publication bias. After screening 2,545 potential articles from the electronic databases, we identified 96 RCTs; comprising of 49 trials on CHM treatment, 44 trials on acupuncture treatment and 3 trials on combined therapy for appraisal. There were 4,861 subjects in the treatment groups and 3,821 in the control groups, with treatment duration ranging from 2 weeks to 4 months. Of the 77 publications written in Chinese, 75 had a Jadad score <3, while 16 of the 19 English publications had a Jadad score of >3. Efficacy was defined as body weight reduction ≥ 2 kg or body mass index (BMI) reduction ≥ 0.5 kg/m(2) . Compared with placebo or lifestyle modification, CHM and acupuncture exhibited respective 'risk ratio' (RR) of 1.84 (95% CI: 1.37-2.46) and 2.14 (95% CI: 1.58-2.90) in favour of body weight reduction, with a mean difference in body weight reduction of 4.03 kg (95% CI: 2.22-5.85) and 2.76 kg (95% CI: 1.61-3.83) and a mean difference in BMI reduction of 1.32 kg m(-2) (95% CI: 0.78-1.85) and 2.02 kg m(-2) (95% CI: 0.94-3.10), respectively. Compared with the pharmacological treatments of sibutramine, fenfluramine or orlistat, CHM and acupuncture exhibited an RR of 1.11 (95% CI: 0.96-1.28) and 1.14 (95% CI: 1.03-1.25) in body weight reduction, mean difference in body weight reduction of 0.08 kg (95% CI: -0.58 to 0.74) and 0.65 kg (95% CI: -0.61 to 1.91), and mean difference in BMI reduction of 0.18 kg m(-2) (95% CI: -0.39 to 0.75) and 0.83 kg m(-2) (95% CI: 0.29-1.37), respectively. There were fewer reports of adverse effects and relapses of weight regain in CHM intervention studies conducted in China than studies conducted outside China. CHM and acupuncture were more effective than placebo or lifestyle modification in reducing body weight. They had a similar efficacy as the Western anti-obesity drugs but with fewer reported adverse effects. However, these conclusions were limited by small sample size and low quality of methodologies.

Identification of a novel prostate cancer susceptibility variant in the KLK3 gene transcript

Genome-wide association studies (GWAS) have identified more than 30 prostate cancer (PrCa) susceptibility loci. One of these (rs2735839) is located close to a plausible candidate susceptibility gene, KLK3, which encodes prostate-specific antigen (PSA). PSA is widely used as a biomarker for PrCa detection and disease monitoring. To refine the association between PrCa and variants in this region, we used genotyping data from a two-stage GWAS using samples from the UK and Australia, and the Cancer Genetic Markers of Susceptibility (CGEMS) study. Genotypes were imputed for 197 and 312 single nucleotide polymorphisms (SNPs) from HapMap2 and the 1000 Genome Project, respectively. The most significant association with PrCa was with a previously unidentified SNP, rs17632542 (combined P = 3.9 × 10⁻²²). This association was confirmed by direct genotyping in three stages of the UK/Australian GWAS, involving 10,405 cases and 10,681 controls (combined P = 1.9 × 10⁻³⁴). rs17632542 is also shown to be associated with PSA levels and it is a non-synonymous coding SNP (Ile179Thr) in KLK3. Using molecular dynamic simulation, we showed evidence that this variant has the potential to introduce alterations in the protein or affect RNA splicing. We propose that rs17632542 may directly influence PrCa risk.

Use of the QuantiFERON-TB Gold test to confirm latent tuberculosis infection in a Canadian tuberculosis clinic

SETTING

Capital Health Tuberculosis (TB) Clinic, Edmonton, Alberta, Canada.

OBJECTIVE

To analyze the QuantiFERON-TB Gold In-Tube test (QFT) results after implementation as a routine test for tuberculin skin test (TST) positive patients.

DESIGN

From November 2004 until January 2007, patients who were TST-positive and were eligible for preventive treatment based on Canadian guidelines, were offered a QFT.

RESULTS

Of 1446 TST-positive patients, only 566 (39.6%) were QFT-positive. Categorized by reason for TST testing, 43.1% of 304 contacts, 32.8% of 348 employment screens and 24.2% of 298 post secondary school screens were QFT-positive. In contrast, 59.7% of 290 immigration screens were QFT-positive. A multivariate analysis found that QFT positivity was associated with older age, larger TST size, high-incidence TB region of birth, history of TB and chest X-ray findings suggestive of previous TB.

CONCLUSION

Implementation of the QFT as a secondary test for latent TB infection (LTBI) can significantly reduce the number of patients given LTBI treatment in a low-incidence country such as Canada.

Metabolic abnormalities associated with mild cognitive impairment in Parkinson disease

OBJECTIVE

To use (18)F-fluorodeoxyglucose (FDG) and PET to investigate changes in regional metabolism associated with mild cognitive impairment (MCI) in Parkinson disease (PD). Cognitive abnormalities are common in PD. However, little is known about the functional abnormalities that underlie the manifestations of MCI in this disorder.

METHODS

We used FDG PET to measure regional glucose metabolism in patients with PD with multiple-domain MCI (MD-MCI; n = 18), with single-domain MCI (SD-MCI; n = 15), and without MCI (N-MCI; n = 18). These patients were matched for age, education, disease duration, and motor disability. Maps of regional metabolism in the three groups were compared using statistical parametric mapping (SPM). We also computed the expression of a previously validated cognition-related spatial covariance pattern (PDCP) in the patient groups and in an age-matched healthy control cohort (n = 15). PDCP expression was compared across groups using analysis of variance.

RESULTS

SPM revealed decreased prefrontal and parietal metabolism (p < 0.001) in MD-MCI relative to N-MCI, as well as an increase in brainstem/cerebellar metabolism (p < 0.001) in this group. In these regions, SD-MCI occupied an intermediate position between the two other groups. PDCP expression was abnormally elevated in the N-, SD-, and MD-MCI groups (p < 0.05), increasing stepwise with worsening cognitive impairment (p < 0.01).

CONCLUSIONS

Early cognitive decline in Parkinson disease as defined by mild cognitive impairment is associated with discrete regional changes and abnormal metabolic network activity. The quantification of these alterations with (18)F-fluorodeoxyglucose PET may allow for the objective assessment of the progression and treatment of this disease manifestation.